fix(graph): adding the same user as multiple members in a group (#3354)

[pbleser-oc]

Description

• make sure the list of members to add to a group is unique, both on the level of the inbound list of member IDs as on the level of the LDAP DNs they resolve to
• remove the corresponding failing test from the list of expected failures

Related Issue

• Fixes Adding the same user as multiple members in a single request results in listing the same user twice in the group #3354

Motivation and Context

When users are added to an existing group, specifying the same user identifier multiple times ended up in that user entry being referenced multiple times in that group, in the IDM as well as in Graph API calls.

That should not be the case as it makes no sense to have the same user referenced multiple times in a group.

How Has This Been Tested?

Test snippets can be found in #3354

Used those snippets on a locally running instance.

Also verified using the test suite:

BEHAT_FEATURE=tests/acceptance/features/apiGraphUserGroup/addUserToGroup.feature:429 \
TEST_SERVER_URL=https://host.docker.internal:9200 \
make -C tests/acceptance/docker/ run-test-only

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)
• Technical debt
• Tests only (no source changes)

Checklist:

• Code changes
• Unit tests added
• Acceptance tests added
• Documentation added

[codacy-production]

Up to standards ✅

🟢 Issues 0 issues

Results:
0 new issues

View in Codacy

🟢 Metrics -14 duplication

Metric	Results
Duplication	-14

View in Codacy

🟢 Coverage 0.00% diff coverage

Metric	Results
Coverage variation	Report missing for f94b6c71
Diff coverage	✅ 0.00% diff coverage

View coverage diff in Codacy

Coverage variation details

	Coverable lines	Covered lines	Coverage
Common ancestor commit (f94b6c7)	Report Missing	Report Missing	Report Missing
Head commit (921ea9c)	84116	19461	23.14%

Coverage variation is the difference between the coverage for the head and common ancestor commits of the pull request branch: <coverage of head commit> - <coverage of common ancestor commit>

Diff coverage details

	Coverable lines	Covered lines	Diff coverage
Pull request (#3356)	13	0	0.00%

Diff coverage is the percentage of lines that are covered by tests out of the coverable lines that the pull request added or modified: <covered lines added or modified>/<coverable lines added or modified> * 100%

¹ Codacy didn't receive coverage data for the commit, or there was an error processing the received data. Check your integration for errors and validate that your coverage setup is correct.

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